Air springs are well known in the art and comprise an elastomeric sleeve which is maintained between a piston member at one end and an end cap assembly at the other end. Such air springs are adapted primarily for implementation in motor vehicles for supporting the vehicle body. The air springs are sealed at the ends to form a pressurized fluid chamber within the sleeve. Reinforcing beads previously have been molded about or within the peripheries of the sleeve ends to provide for a fluid tight seal with the piston and end cap assembly. It has also been known to seal the ends of the sleeve forming the air spring by means of complex mechanical structures, typically incorporating metallic plates and the like secured by means of bolts or other fastening means. These sealing structures are both time consuming and expensive in implementation.
Previously known structures of the general nature set forth herein are shown in U.S. Pat. Nos. 2,874,458; 2,977,134: 3,038,717: 3,790,147: 4,325,541; 4,506,910: and British Pat. No. 907,555. None of these references, however, teach an air spring which may be quickly and effectively formed from a tubular elastomeric sleeve without a separate reinforcing bead and wherein the bead is formed and sealed by simple engagement of snap-fitting together parts of metal and/or plastic. The teachings of the prior art have been expensive as to both time and material involved and, due to the metallic parts and separate bead rings previously used, have been a source of undesired weight in a vehicle.
Furthermore, in existing air spring as the internal pressure increases the separation forces acting on the sleeve end seals increases thereby limiting the amount of internal pressure which can be utilized for the air spring.
Accordingly, there is desire in the art for a simplistic and inexpensive air spring which is formed from a tubular elastomeric sleeve, the ends of which are sealed by mating parts which seal the unit and form a pressurized fluid chamber without requiring the installation of separate reinforcing beads within the sleeve ends during formation of the tubular sleeve.